Aspects of electrode erosion in high-power vortex stabilized arc lamps

Electrode erosion (especially anode erosion) is still an important problem for high-power vortex stabilized arc lamps. A study of the electrode erosion mechanisms has therefore been carried out in vortex stabilized arcs operating at a maximum input power of 40 kW. It was found that three factors are important in the removal of electrode material: evaporation caused by thermal loading, ablation due to time varying stresses, and corrosion resulting from the presence of impurities in the gas. It was also found that the first two factors, and hence the erosion rates, can be affected significantly by the orientation of the electrodes and the presence of an external magnetic field.